Support



April 16 1946 l. 4E. MoURoM'rsEhFF r-:rAL

SUPPORT Filed May 9, 1942 INVENTORS 6. M .D//V/V/C/C BY W um WMLATTORNEY EEN .1 Q l n Patented Apr. 16, 1946 .t

SUPPORT Ilia E. Mouromtseif, Montclair, and George M.

Dinnick, Bloomield, N. J., assignors to Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaApplication May 9, 1942, Serial No. 442,360

7 Claims.

This invention relates to supports and more particularly to electrodesupports in electron discharge devices.

Certain electron discharge devices, particularly of the ultra highfrequency type, develop high temperatures in normal operation, and theheat conducted along the leadin supports has placed undue strain on theseal between the support and glass envelope. Cracks and defective tubeshave resulted, making it necessary r`to devise means for reducing thetemperature gradient Without impairing the electrical conductivity.'I'he present invention is directed to this problem and offers asolution thereof.

The objects of the invention accordingly are to overcome the effects ofhigh temperature gradient between electrode and envelope upon the regionwhere the lead-in for the electrode is sealed with respect to theenvelope.

Another object of the invention is to effect a temperature protectionwithout adversely affecting the electrical efficiency.

A further object of the invention is to maintain rigidity of the supportwhile performing the desired obstruction to heat conduction.

Yet another object of the invention is to obtain a simple construction,one readily and economically fabricated, and one which lends itself toeffective outgassing or evacuation.

Still further objects will appear to those skilled in the art as thedescription progresses both by direct recitation thereof and byimplication from the context.

Referring to the accompanying drawing in which like numerals ofreference indicate similar parts throughout the several views;

Figure 1 is an elevation of an electron discharge device embodying thepresent invention;

Figure 2 is a sectional view on line II-II of Figure 1; and

Figure 3 is a cross section considerably enlarged on line III-III ofFigure 2.

In the specific embodiment of the invention illustrated in said drawing,the reference numeral I indicates an evacuated envelope, here indicatedas of glass. At the top of this envelope two protruding stems II areprovided which constitute sealing and supporting means for lead-in postsor supports I2, description whereof will follow presently, as theessential feature of the y present invention. These posts or supportshave been here illustrated as means for suspending an anode I3 atapproximately the middle part ot the envelope. Details of constructionof the anode are fully described in a concurrent application herewith,Ser. No. 442,361,11ed in the names of G. M. Dinnick and J. P. Quitter.Sufi'lce it to say' that said anode, as shown, is of an elongatedconfiguration with a metal lining I4 for carbon block body members l5each of which is suitably recessed for receiving grid I6 and cathodes I1together constituting the triode of the electron discharge device. Theanode includes lateral extensions I8 of looped construction by which aself contained oscillatory circuit is provided in the device.

The device, as shown, is accordingly one generating ultra high frequencyoscillations, vis capable of producing high power and unavoidablydevelops high temperature in the anode. Al-l though this temperature isundesired, neverthe# less it is present as a necessary evil and must becoped with-to overcome detrimental effects. A most serious and ruinouseiect is conduction of the heat up the anode posts or supports to theglass seal, and due to the intensity of the heat, in conjunction withdifferent coeicients of expansion of metal and glass, cracks andcrevices appear, air leaks in, and the device becomes useless".

According to the present invention, the posts or supportsV I2 here shownas employed for suspending the `anode I3 are constructed of severalparts, namely a stud or electrode attaching portion I9 constituting oneend section, a glass adherent outer section 20 and an intermediate heatdeterring section'2l all in axial alinement and rigidly securedtogether. By preference, the electrode attaching section is ofelectrically conductive metal, preferably molybdenum, and comprises athreaded shank portion 22 passing vertically through the anode and heldthereon by a bottom nut 23 acting in opposition to a shoulder on saidsection immediately above the electrode and formed in consequence of theprotruding body of the said section having greater diameter than saidshank portion. At the top of the body portion of said section I9 is areduced neck 24.

Encircling said neck 24with its outer surface forming a continuation ofthe body portion surface of the electrode attaching surface, is ametallic tube constituting the said intermediate heat deterring section2l. This section, by virtue of being tubular, has a minimum mass butadequate rigidity which introduces desired heat deterring effect withoutweakening the structure of the complete post. Furthermore, the metalemployed is preferably one which is adequately conductive of electricalcurrent or energy. but which is highly resistive to conduction of heat.The preferred www material used is an alloy of nickel, cobalt and ironsold under the trade name of Kovar and more fully described in patent toScott, No. 2,062,335. Suitable rigid attachment of the two sections maybe obtained, and as one means a rivet 25 is employed which extendsdiametrcally through juxtaposed parts of the' neck and tube.

.At the upper end ofY tubular or intermediate section 2| another neck 26is mounted therein,

this said neck depending from the glass adherent outer section 20. Thecontiguous outside surfaces of the intermediate tubular section andglass adherent outer section are preferably flush, Uni-i' cation ofthese two sections. may be obtained 1n` suitable manner such as by useof hard solder, by welding or otherwise. Preferably the said outersection is composed of tungsten for its desirable characteristics ofelectrical conductivity and ability to form adhesive union with glassapplied thereto in molten or highlyA plastic state, and because of thenearness of coefficients of expansion of glass and tungsten.

The glass stem I I forming part of the envelope I is of elongatedcharacter for applying the contacting or pinch region 2l of glass to thepost at a considerable distance from the anode and on the far endportion of the outerpost section. The seal is accordingly protected bydistance and by intervening heat resisting or deterring'.r material inthe post from heat from the anode. The intermediate section 2|,whilereceiving the attaching necks of the adjacent sections, is, for thegreater part of its length-entirely hollow, the

structure lending itself to effectively cleterring transition of heatand obtaining thereby and by virtue of the heat-resistancecharacteristic ofthe Kovar of which it is composed, a desirably highheat gradient between end portions ofr said section. Electricalconductivity of thefKoVar is adequate to avoid undesirable opposition tothe transition of electrical energy, Holes 28 may be provided throughthe side wall ofthe said section for assisting in fully evacuating gaswithin said section when evacuating the device envelope.

Various modifications and-changes as to precise structure `vandmateria-1s aref contemplated means to one end section; successivesections` having their entireA support from saldi-means throughsuccessive-attachment to eachother.Y

2. An electrode support-comprising an elongated composite rigid memberof sections successively juxtaposed endwise to each other and of whichone section is of material and crosssection more resistive to heatconduction than a next adjacent section, said sections havingsubstantially equal diameters and continuity of exterior surfaces fromone section to the next, and means rigidly mounting said support byattachment of said means to one end section, successive sections havingtheir entire support from said means through successive attachment toeach other,

3. An electrode support comprising a rigid member of successive sectionsjuxtaposed each at the end of another of which one section is interposedas an intermediate section between two other sections adjacent thereto,said intermediate section being less heat conductive than the othersections adjacent thereto, said sections having substantially equaldiameters and continuity of exterior surfaces from one section to thenext, and means rigidly mounting said support by attachment of saidmeans to one end section, successivev sections having their entiresupport from saidmeans through successive attachment to each other.

4. An electrode support comprising a plurality of elongated sectionsjuxtaposed endwise successively -to each other whereby one section isintermediate of two other sections, said intermediate section beinghollow for the entire length thereof between the two other sections andless conductive of heat than said other sections.

5. An electrode support comprising a plurality of sections of which onesection is tubular from end to end and another section solid, the solidsection having an end portion inserted for a short part of the length ofthe tubular section and secured thereto and leaving the major part ofsaid tubular member hollow for maintaining low heat conductivity of saidtubular section,

6. An electrode support comprising a plurality of sections of which onesection is tubular and another section solid, all ci the plurality ofsections being physically alined and electrically conductive andelectrically in series, said sections having substantially equaldiameters and continuity of exterior surfaces throughout the length ofeach and fromone section to the next, and said hollow section presentingobstruction to heat conduction more effectively than said solid section.

7..An electrode support comprising a plurality of sections of .which onesection is tubular for its entire length and of high resistance to heatconduction, and of which two other sections of less resistance to heatconduction are juxtaposed to the tubular section at the ends thereofwith the tubular section intermediate thereof, and all of said sectionsbeing in electrical series and having good electrical conductivitycharacteristics.

GEORGE M. DINNICK.

